The quake, which reduced large parts of Kathmandu to rubble,
is not the 'great Himalayan quake' that the region has been bracing for, experts
say the worst is yet to come.

Down To Earth magazine quoted Roger Bilham, geologist with
the University of Colorado Boulder who studies the seismicity of the Himalayan
area as saying, "At a magnitude of 7.9 on the Richter scale, the April 25
earthquake has caused devastation but it is not the anticipated “great
Himalayan earthquake”. This does not qualify as a great earthquake which needs
to be of magnitude 8".

Prof Sankar Kumar Nath of IIT Kharagpur, who has studied
seismic activity in the Himalayan region, had an even gloomier outlook.

“This earthquake would only be classified as medium in terms
of energy released. That area, the 2500-km stretch from the Hindukush region to
the end of Arunachal Pradesh, is capable of generating much bigger earthquakes,
even nine on Richter scale,” he said. “If you look at it differently, we are
actually lucky that only a 7.9-magnitude earthquake has come. I would be very
happy to have a few 7.9-magnitude earthquakes than a 9-magnitude earthquake
which would be absolute disaster. The trouble is that in terms of energy
release, which is what causes the damage, it would take 40 to 50 earthquakes of
magnitude 7.9 to avoid an earthquake of magnitude 9”.

The Himalayan mountains and the Tibetan Plateau beyond, as seen in this photograph taken from the International Space Station, have been pushed up as the Indian subcontinent has shoved into the underbelly of Asia. This slow-motion tectonic collision creates the potential for a great quake that could kill millions of people. (Source: Wikimedia Commons)

The last major earthquake (magnitude 8.4) occurred in 1934,
killed an estimated 17,000 across both Nepal and India. Since then, researchers
have been tirelessly studying the 'fault' lines of the last earthquake to
predict the next one, but failed to do so.

Seismologist James Jackson, head of the earth sciences
department at the University of Cambridge in England, was in Kathmandu just a
week ago. Following the 7.9-magnitude earthquake, he told Associated Press that
scientists knew "they were racing against the clock,".

Jackson, who was part of a 50-strong scientists and
researchers team from across the world, said that the devastation would be huge
not because of the size of the seismic activity, but because of population
pressure and degradation of the environment.

And this has been one of the biggest issues in the region.

The exploding population in the region greatly increases the
risk of casualties. The Times of India quotes from a study called the Himalayan
Seismic Hazard, published in Science magazine in 2001:

"The population of India has doubled since the last
great Himalayan earthquake in 1950 (in Assam). The urban population in the
Ganges plain has increased by a factor of 10 since the 1905 earthquake, when
collapsing buildings killed 19,500 people. Today, about 50 million people are
at risk from great Himalayan earthquakes, many of them in towns and villages in
the Ganges plain. The capital cities of Bangladesh, Bhutan, India, Nepal, and
Pakistan and several other cities with more than a million inhabitants are
vulnerable to damage from some of these future earthquakes".

The devastating impact to life and property caused by
natural disasters in the Himalayan region was painfully evident during the
devastating cloud burst in Uttarakhand which also claimed over a thousand
lives.

As pointed out by Jay Mazoomdar in an article: "way too
many properties and lives came in the way of the Mandakini and Alakananda on 16
and 17 June because we placed ourselves where we were never supposed to. That
part, the part that made a natural calamity an enormous human tragedy, is
entirely and unquestionably manmade." He added that the arguments of
development hardly came into play, given the ecologically sensitive nature of
the region.

This map shows the zone where India and Asia are colliding as a result of tectonic movement. Shaded areas with dates near them show where great earthquakes have occurred. The bars show how much slip could occur in those regions during an earthquake, on a scale of 1 to 10 meters. The red portions of the bars show the potential for slip based on on how much strain has accumulated since the last great earthquake. The pink portions show possible additional slip that could occur. The inset diagram shows a cross-section through the Himalayan arc, illustrating how India is sliding beneath southern Tibet. (Source: Himalayan Seismic Hazard, by Roger Bilham, Vinod K. Gaur, Peter Molnar, Science, August 2001)

Following the Uttarakhand tragedy, many promises were made
to review development work and work towards creating an ecologically viable
model that would no longer endanger the area.

However, the Congress government in the state has since
abandoned work on the much-delayed zonal master plan for the Bhagirathi Eco
Sensitive Zone -- which was to be created by a 2012 notification that declared
4179.59 sq km in the watershed of the Bhagirathi river between Gomukh and
Uttarkashi as a green zone to safeguard it from unplanned growth.. The Indian
Express notes that "days after Environment Minister Prakash Javadekar
refused to modify the ESZ notification, the ministry reversed its stand on
January 13 at a PMO meeting chaired by Nripendra Misra".

Given the magnitude of the Uttarkashi disaster, it is not
difficult to imagine how much more destructive an earthquake in the same area
would be. Given the government's cavalier attitude toward earthquake safety and
development in the Himalayas, we may be facing our very own humanitarian
disaster -- and it won't even have to be the 'big one' for it to really hurt.